Kirby was the last survivng member of an Outer Rim world known as Karbya. When he was a teenager the Sun that his planet orbited began to go super nova, using brute strength Kirby escaped the planet by stealing a cargo ship and managed to escape out of the blast radius. Despite this the explosion still heavily damaged Kirby's ship and he was forced to make a crash landing on Alzoc III, and Imperial planet currently undergoing inspection by Darth Vader.
When the Imperials salvaged Kirby's body Vader sensed the Force within the boy and had him rebuilt as a cyborg. Kirby was then sent for training to join the ranks of the Imperial Inquisitors.